In recent year, with increasingly advanced technology industry, as well as increased demands for various types of consumer electronics product, resonators have become clock components for cars, TVs, cameras, portable electronics and other electronic equipments.
The electrostatically driven microelectromechanical (MEMS) resonators have been commercialized as frequency reference devices with an acceptable accuracy. The impedance of the MEMS resonators exhibits a high impedance, thereby causing limitations in applications of higher frequency and difficulties in processing back-end circuits. In addition, feed through capacitor signals of capacitive resonators are very large and thus have higher feed through. The MEMS resonators generally need a complex structure release etching process, and thus are difficult to be fabricated and are difficult to be integrated with complementary metal-oxide semiconductor transistors (CMOS) processing.